Method of treating hydrocarbon



'April 19,v 1938. Re. 20,703y

I METOD OF TREATING HYDROGARBON, DISTILLATES I R. c osTERsTRoM original FildApril 19.' '1929 om f Indalia; c. osta-gif A as Ranma Apr. 19,1938

'PATENT OFFICE METHOD or marmo mnoomon ms'rnaaras Rudolph C. stersti'om, Kenilworth, lli., signor to The Pure Oil Company. Chicago, lll., a corporation of Ohio original N6. 1,891,3zs, mea Februar-y 14, 1933,

Serial No. 356,569, April 19, 1929. Application lor reissue 744,563

This invention relates to an improved method of treating hydrocarbon 'distillates particularly distillates obtained from cracking stills, and has for its primary object the provision of a method whereby undesirable compounds present in such distlllates, for example, gum-forming and colorimparting bodies, may be readily removed from the distillates and an end product obtained of a purified character having a boiling range comv parable with that of gasoline.

'I'he value of fullers earth vas a treating agent for removing undesirabley compounds from cracked petroleum vapors is well understood by oil renners. The operation is based on the theory that the oil vapors while penetrating a bed of fullers earth react to polymerize the undesirable compounds which discolor the oil and produce gum deposits therein.

'I'he present invention has for an outstanding object the provision of a system wherein greater and more improved contact is obtained between the oil vapor undergoing purification and the fullers earth than has heretofore been attained,

to the end of providing for a more efllcient process in the matter of more completely eliminating the undesirable compounds present in the oil at the lsame time to carry out the process in an economic manner wherein clay waste particularly is avoided. Itis another object of the invention to provide a process oi this character wherein the oil to be treated, together with inely divided fullers earth, is passed in unison through a heated zone and subjected to conditions of temperature and pressure necessary'to eiect polymerization reactions, and wherein the oil and clay after passing through said zone are admitted into an ex'- pander for the purpose of separating the liquid clay-polymer containing fraction' of the oil from the lighter vaporous fraction, and wherein provision is made for passing the said lighter and vaporous fraction through a stationary bed of fullers earth so as to eiectively remove from the desired oil all color and gum-forming bodies to the end that the final product when condensed and liquefied may be stored, transported and otherwise handled in a customary commercial manner under ordinary conditions without suffering loss of value by reason of gum formation or lack of proper color. y

For afurther understanding of the invention reference is to be had to the following description and the accompanying drawing wherein the iigure represents a diagrammatic view disclosing conventionally the apparatus used in carrying the present invention into operation.

September 18, 1934, Serial No.

Referring more particularly to the drawing the numeral l designates a cracking still, converter, reaction chamber -or distillation unit, whichever the case may be. In this connection it will be understood that the invention may be used in the purifying of vapors released from (l) a vapor phase converter or other high temperature unit for effecting the molecular decomposition of the oil while the latter is in the vapor phase; (2) the cracking still of a liquid phase converter; (3) the reaction chamber or expander of a liquid phase converting system; or (4) a pipe still, a shell still or other source of hydrocarbon vapor supply. In all of these operations lvapors vmay be produced containing undesirable compounds. sion this is particularly true, wherein the released vapors must be treated to remove therefrom gums,

In` vapor phase systems of ccnvercolor, odor producing and other compounds which require elimination'before the end product can be commercially distributed. While a cracked vapor phase distillate especially needs treatment, distillates obtained from Cliquid phase cracking systems also require similar treatment and in many instances vapors from distillationv units wherein no conversion or cracking of the oil under treatment takes place.

From the unit l vapors which are generated therein pass by a pipe 2 to an evaporator 3. The materials which are unvaporized in the unit or which condense in the evaporator coll-ect as liquids in the bottom of said evaporator and are Withdrawn by way of the line 4 preferably as fuel oil. The vapors remaining in the evaporator 3 pass overhead-by way of the line 5, and enter a 1 fractionating tower B of any suitable construction. In this tower the liquid'condensate which accumulates in the bottom drum 1 thereof is Withdrawn by way of a pipe line B and may, if desired, be employed as recycle stock or, in other words, may be recirculated through the unit or still l for additional heat treatment. fr

.'I'he vapors which are discharged from the ytop of the tower 6 are conducted by way of the pipe line 9 into the lower portion of a scrubbing tower Ill. The top of this tower is provided with a line I l by means of which liquid reflux oil commingled with fullers earth, nely divided clay or diatomaceous earths are introduced into the top of the tower lll for direct contact with the ascending va pors passing through said tower. The claybearing reflux oil descends through the tower I0 in counter-current flow to the ascending vapors, thus removing from said vapors all highy boiling point materials which may be entrained in said stationary condition within the tower;

vapors. In addition, the vapors are subjected to direct contact to a limited degree with the clay-treating material in order to remove from the vapors the undesirable constituents which it may possess 'I'hese vapors pass overhead from the tower I by way of the pipe line I2 and may circulate through a condenser I3 and then to a storage tank I4 as a treated end product.

There collects in the bottom of the tower il) a quantity of liquefied hydrocarbons, consisting -ofthe reflux oil introduced by way of the line Il and the heavier condensed oils obtained from the vapors flowing through the tower i0, which oils are mixed with the clay treating materials introduced by way of the line Il, or by the hopper lia. I'hese condensed oils and clay treating material pass from the tower i0 by way of a pipe line I5 in which is provided a control valve IB and are led into a pump I1, in order that said oils, together with the thoroughly intermingled or commingled clays may be forced through a pipe line Il leading to a coil bank IS arranged within the setting of a pipe still 20. Through the medium of the pump Il relatively high pressures are maintained on the oil under heat treatment in the pipe still. These pressures may be approximately 200 pounds per square inch and at the same time the oil within the pipe still is heated to a temperature of approximately 650 F. These temperatures and pressures have been found to be highly effective in securing proper reactions in the matter of eiIecting the polymerization of` undesirable compounds. I have observed that the higher the temperature the greater is the eiliciency of the treating material and for-this reason I employ temperatures con` siderably higher than those utilized in prior proc-l esses. Even at the temperatures and pressures specified the oil thus undergoing treatment-remains or is maintained in the vapor phase. I am aware of the fact that it has been proposed to keep the oil under treatment in the liquid phase by the use of high pressures and whilein contact with the clay-treating material and thento suddenly release said pressures by permitting the oil, to expand rapidly in an enlarged fractionating column or othervenlarged chamber. In the present invention, however, 'while'high temperatures and pressures are used no eifort is made to maintain the oll in the liquid phase strictly, the pressures utilized being high enough to thoroughly impregnate the clay with the oil under treatment.

After circulation through the coil bank of the pipe still the oil is passed through a pipe line 2| provided with a pressure release valve 22, and thence into a fractionatingtower 23, where the oil vapor may be maintained at a pressure slightly above atmospheric. The clay and the polymerized hydrocarbons in liquid form are collected in the bottom of the tower 2l and may be continuously removed therefrom by a pipe line 2l, the

lighter or desired fractions passing overhead from.

said fractionating tower 22 by way of a pipeline 2l to a tower 25. fuiler's earth through which theV oil vapors penetrate, the fullers earth being maintained in a By con'- tacting with the stationary bed of fuliers earth, which is designated by the numeral 26, the faint or final traces of impurities which may remain in the distillate following release yfrom the fractionating tower 23 are completely removed from the oil, and the latter is then conducted to a condenser 21 and following cooling and liquefaction to a storage tank 28, the heavy polymerized frac- This tower contains a bed of tions being removedV from the tower by way of the polymer outlet 2l.

The liquefied hydrocarbons which are collected in the tank 28 are'substantially free from compounds which tend to discolor the same or to produce gums or resinous substances therein. 'I'hese oils since they possess the boiling range of ordinary gasoline may be used as moto'r fuels and A'possess a water-white color, a satisfactory odor, good stability in color upon exposure to light or upon standing and possess a very low or practically negligible gum content, which remains low even after long periods 'of storage.

What is claimed is:

i. Themethod of decolorizing and degumming petroleum oils comprising adding a catalytic material in nnely divided form to a flowing stream of oil, subjecting the owing stream o! said mixture to temperatures in excess of 500" F. and to pressures in excess of 200 pounds per square inch. releasing said superatmospheric pressure, ,discharging the mixture into a vaporizing and fractionating zone, separately discharging treated oil vapors and catalytic materials from said zone, and passing the treated oilvapors through a sta' tionary bed of said catalytic materials.

2. The method of treating previously untreated cracked gasoline distillates which consists in mixing same with a treating material comprising a solid, finely divided adsorbent, heating the` mixture while maintaining an autogenous pressure thereon until a substantial improvement in the oil material results, then releasing said pressure and distilling of! the fractions of `the iinal gasoline and subjecting the produced vapors to treatment with an adsorbent purifying material and condensing the vapors so treated. 3. The method of treating previously untreated gasolinedistillates which consists in forming a mixture of said distillate and a treating material comprising a solid, finely divided adsorbent, heating said mixture under superatmospheric pressure and for a period sufilcient to bring about a substantial improvement vof the oil, separating the lighter desired fractions by releasing the pressure on the mixture, then contacting the so separated vapors with fresh treating material. n

4. The method of vtreating raw gasoline distillates which consists in subjecting said 'distillate to contact with va solid adsorbent catalytic material while under a pressure in excess of 200 pounds per'square inch and a temperature in excess of 500'v F. for a period sufcient to bring about a substantial improvement of said distillate, re-

ducing the pressure upon said treated distillate v comprising a solid, finely divided adsorbent, heating said mixture under sufiicient pressure to thor-A oughly impregnate the adsorbent with the oil under treatment and for a period of time sumcient to bring about a substantial improvement of the oil, separating the-lighter desired fractions by releasing the pressure on the mixture, then contacting the so-separated vapors with fresh treating material.

RUDOLPH OSTERSTROM. 

